Improvement in telegraph-transmitters



3 Sheets--Sheet1.

Patented.Aug..17,1875.

H. MIDDLETON.

Telegraph Transmitters.

I W. i g g my..- 1 W 3 Sheets-Sheet 2. H. MIDDLETON,

Telegraph Trgnsmitters.

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I No. 166,712, Patent'ed Aug.17,187'5.

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, 3Sheets--Sheet3 H. MIDDLETON.

Telegraph Transmitters.

N0,166,712, PatentedAug.17,1875.

fly 6 N. PETERS. PHoTo-u'mOGRAPHLR, WASHINGTON, u c.

NITED STATES HENRY MIDDLETON, OF CHARLESTON, SOUTH CAROLINA.

IMPROVEMENT IN TELEGRAPH-TRANSMITTERS.

Specification forming part of Letters Patent No. 166,712, dated August17, 1875 application filed J nne 10, 1875.

To all whom it may concern:

Be it known that I, HENRY MIDDLETON, of Charleston, county of Charlestonand State of South Ua'rolina, have invented new and useful Improvementsin Telegraph-Keys, and I do hereby declare that the following is a full,clear, and exact description thereof, reference being had to theaccompanying drawings making part of this specification, in which-Figure 1 is a perspective view of my telegraph-key, with the coverraised and front of box removed, so as only to expose to view the frontends of the finger-keys, upon which the letters of the English alphabetare placed. Fig. 2 is a vertical central section through the key,looking toward the right-hand side of the key-box. Fig. 3 is a top view,with the cover of the key-box thrown fully over. Fig. 4 is a verticalsection through the key-box, looking at the right-hand side of the same.Fig. 5 is a vertical transverse section, looking toward the front of thekey-box. Fig. 6 is a vertical central section of one of the shortfinger-keys and the connections thereof. Fig. 7 is a like view of one ofthe long finger-keys. Figs. 8, 9, and 10 are inverted views, somewhatenlarged, of the metallic letter V and so formed as to make the dot andthe dash of the Morse alphabet when my key is in operation, and

said letters right side up.

A A is the box or case, which has attached to its top the binding-postsB and B. The cover being raised shows the key-board O. The finger-keysare twenty-seven in number, and of two different lengths-dong ones, asat K, and short ones, as at K, alternating with one another. Twenty-six(26) of these fingerkeys are marked with the letters of the Englishalphabet at their front ends, and when my key is properly connected withvoltaic batteries and registering-instruments, the act of depressing anyone fin ger-key communicates to such registering-instruments a system ofsuch makes and breaks in the voltaic circuit as the Morse alphabetadopts to represent the corresponding letter written on the depressedkey. The twentyseventh fingerkey has marked on it the symbol 8t, and ondepressing the finger-key in question the proper system oftelegraph-characters used to represent that symbol will be communicatedto the registeringinstruments. Moreover, I reserve to myself the rightof adding as many more finger-keys to my instrument, to express eithernumerals, abbreviations of words, or any other signs, as I may deemproper.

My keyis composed of three principalpartsviz., "the key-board, theletters, and "the battery-connections, which I will now describe in theabove-mentioned order.

The key-board (see Figs. 1,2, and 3) consists of a flat supporting-pieceof wood, D, to which the brass pieces E and E are fastened at suitablepoints. A brass rod, R, passes through holes drilled in the upper endsof E and E. A third piece of brass, E is placed about the middle of therod, to strengthen and give further support and stability to the same.The fin ger-keys K and K have holes bored in them, through which holesthe above-mentioned rod R passes, for the purpose of supporting thefinger-keys and permitting them to turn upon the rod as an axis. Thefingerkeys K and K are made of brass or other good conductor, of theform and shape shown in the drawings.

Long and short finger-keys are placed alternately for the purpose ofgetting the greatest number of such keys into a given space. In thefront end of each of these keys is a hole containing an insulating-tubeof wood, a, or other good non-conductor, and in the tube is fixed aconductingcore, a, of brass or copper,

which extends from the bottom of the key upward, so as to project asmall distance above the surface of the finger-key, as shown. Insulatedcopper wires w are fastened in such manner to the lower part of eachcore a as to secure electrical communication between the core and'itsrespective wire. These wires are twentyseven in number, and extendbackward under'the finger-keys and parallel to their length, and are allput in electrical communication with the metal strip P. Springpieces ofbrass, as at .60 are soldered to the finger-keys at a short distancebehind the metal cores a and project forward over them, but are soarranged and adjusted that they do not come in contact with these coresuntil the finger is pressed down upon them. These brass springs a are oftwo difi'erent shapes. Those on the long keys have a thin non-conductorlaid upon them, as at a and upon this is fastened a letter of thealphabet. Those springs which are attached to the short keys have woodenor ebony tops a, like the black notes of a piano, and upon these theproper letters are fastened.

The farther ends of all the finger-keys are made cylindrical, as shownin the drawings, so that spiral springs g, of silver wire, may workeasily on them. The front end of each spring g is fastened to itsrespective key in such a manner as to secure good electricalcommunication between the two. The back ends of the spiral springs arestraightened out, so that they may pass easily through small holes madein the L-shaped pieces h, which are attached to their respective keys,as shown. After passing through the holes in the L-shaped pieces h theends of the silver springs project a little way and then terminate,their ends pressing against the surface of the metallic letter V placedopposite each finger-key, and rubbing over the surface of the letter asthe key is raised. Under each key a spiral spring, S, is placed, inorder to restore the key to its proper position after it has beendepressed. These springs have their upper ends resting against woodenstrips t, which are glued to the under surface of the keys, and servethe double purpose of protecting the insulatingcovering of the copperwire from being injured by the spring, and also of preventing the upperportion of the spring from slipping. The lower portion of each spring isfixed bya small wooden peg, t, which projects from the supporting-pieceD, and passes into the hollow of the spiral. A wooden bar, J, runs underthe finger-keys, across the end of the key-stand D, and behind thewooden pieces W, to which it is fastened. Into the bar J twenty-sevenvertical holes are bored, so as .to receive twenty-sevenadjusting-screws, m.

The keysrest upon these screws when the instrument is not working. Asecond wooden bar, L, is placed above the keys, and carries twenty-seven adj ustin g-screws, n, which limit I the upward movement of thekeys.

To facilitate further the adjustment of the various parts of my key Ihave so constructed it that the key-board proper may be removed from theinstrument-box by taking out two screws which pass upward through thebottom of the instrumentbox into the key-stand D, when the key-board maybe drawn out.

The Zetters.The letters are formed of pieces of brass, as at V, thestems of the pieces bein g rounded 01f, so as to slide horizontally intoholes made for them in the brass bar Q. Clamping-screwsware placed inthe upper part ofthis bar, in such manner that they can be made toadjust the position of the metallic letters V The bar Q is supported bythe brass pieces T and T, which brass pieces are fastened to the bottomof the key-box. Morse characters are made by cutting out channels in thefiat fronts of the pieces V so that ridges of varying width and numbercorrespond to the dot or dash of the letter they are intended torepresent. Thus, to represent the letter A the brass piece V is prinoiple.

cut as in Figs. 8, 9, and 10, the channels beingfilled up, as at as,with some. good nonconductor, as a piece of vulcanite or ivory.Moreover, two more pieces of vulcanite are inserted in channels at theend of the terminal ridges of the given letter, for the purpose ofbreaking the electrical circuit when the key is at rest, both before itbegins andwhen it ends its motion. A groove or channel, 2, is made inthe center of the said metallic letter V, as in Figs. 8 and 10, in orderto keep the point of the springs g in position when sliding over orscoring over the letter. Furthermore, this groove or channel is deeperin the middle than toward the ends, being cut into an arc whose radiusis the perpendicular distance between the axis of the rod R and thefarther end of any one of the silver springs g, asthe case may be. with,as indicated in Fig. 9, the whole front surface of the letters is curvedinto arcs whose radiuses are the same as above mentioned.

The battery-c01mecti0ns.A binding-post, B, on the top of theinstrument-box, has attached to its lower part a wire, 0, through whichelectrical communication can be established between said binding-postand the bar Q, and through the bar to the metallic letters V, which itsupports. To the lower part of the binding-post B the wire f isattached, to connect this binding-post with the metal spring Y, whichspring is placed against the inside of the instrument-box, and pressesagainst a metal projection, U, Figs. 3 and 5. This projection hasattached to it one end of a wire, 0, Figs. 3 and 5, the other end of thewire being connected with the metal strip 1?. These connections are somade that electrical communications can be established between thebinding'post B, the wire f, the spring Y, the projection U, the wire 0,the strip P, the several wires 20, and the metal cores a of thefinger-keys K and K.

Furthermore, the spring Y, whose connections have just been described,permits the key-board proper to be removed from the instrument-boxwithout unfastening any of the bat-tery-connections, such as wires,screws, &c.,

while the act of restoring the key-board to its place automaticallyrestores the wire-connec' tions between the binding-post B and theseveral keys of the key-board. A circuit-closer, N, Fig. 1, on top ofthe instrument-box enables the key to be cut out when desired. Thecontact of this circuit-closer is broken when the key is to be used forsending messages.

The method of working my key is as follows: The key is supposed to beconnected with batteries, instruments, line-wire, earth, 00., in thesame manner as the Morse key, and can be worked upon either the closedor open circuit Let, now, any finger-keyas, for example, the one havingthe letter A on its forward end, as in Fig. 1be depressed by the finger;then, the spring-piece a? being pressed against the core a under it,(see Fig. 2,) the circuit is completed from the binding- If, however,the groove be dispensed post B to the metal body of the finger-key K,

and consequently to the end of the silver spring g, with which that keyis in electrical communication. As the farther end of key K rises, thespring g passes from the lowest piece of vulcanite set in the metallicletter V against which it is resting, and comes into contact with thefirst brass surface of said letter, which corresponds to the dot of theMorse character for A, and completes the circuit of the battery. As thespring moves on the vulcanite piece with which it next comes in contactit breaks the circuit, which is again restored as the spring reaches thenext exposed brass portion of the metallic letter Vi, used to representthe dash of A. After passing this last brass surface the terminalvulcanite piece breaks the circuit, and shortly after the motion of thekey is stopped by the adjustingscrew a. As soon as the operator feelsthe finger-key stop he moves his finger from the spring a and the springrises. The connection is thus broken between a and the core 00, when thespring 8, under the finger-key, restores it to its first position. Thefinger-key, however, does not operate on its downward movement over theface of the metallic letter V owing to the fact that the circuit isbroken, as above described. In the same manner any other finger-key, onbeing depressed, completes the battery-connections, in such manner as torepresent the Morse characters which correspond to the English letters,which are represented on the front ends of the fingerkeys.

My key can be used to work either Mors instruments or chemical-telegraphapparatus, and by means of it messages can be transmitted between twopoints faster than by an known method.

Any one of the keys of my instrument, on being depressed once,communicates to registering-instruments the letters written on it. Now,in the Morse key it has to be depressed many times in succession to makea single letter; hence, it will easily be seen that any instrument thatmakes one letter by a single touch can write faster messages than onethat takes many touches to make one letter, all other things beingequal.

In the chemical telegraph a key-board and set of keys are so arrangedthat by striking or depressing any one of them once the key so depressedwill punch in a strip of paper a series of holes to represent the letterwritten on the depressed key. After the strip of pa- .per has beenprepared by the punching-machine it has to be reeled on complicatedmachinery, which, on being set in action, transmits to the distantstation what may have been written on the punched paper.

If my key is directly connected to the wires of a chemical telegraph,on' depressing the keys the signals are instantly communicated to thedistant station; the advantage in speed over the ordinary method beingthat no time is consumed in placing the paper in the punching-machinesby the rehandling of the paper to place it on the reeling-machines, andno time is lost in the reeling off,

&c., the paper by the cumbrous machinery at present in vogue. It beingassumed that the keys on my instrument can be depressed with the samerapidity that the keys of the puncher of the chemical or automatictelegraph are worked, the time to transmit a message by my machine isthe same as the time to punch a message for transmission by theautomatic system.

Second. My key is applicable to duplex, quadruplex, or multiplex systemsof telegraph, it being merely substituted for the ordinary Morse key,the battery-connections being exactly the same both for the Morse keyand my key.

Third. My key enables the chemical telegraph to be used for alltelegraph business whatever, since from its extreme simplicity, theabsence of complicated machinery, and the fact that it requires but asingle unskilled operator to work it, the chemical telegraphs can beused with economy and profit at waystations, small towns, villages, &c.,while up to the present time the great expense attending the working ofthe automatic system has precluded its use except in large cities andtowns, where its chief business was the trans-' mission of press-matter,&c.

Fourth. By the employment of my key in connection with duplex ormultiplex electromagnetic telegraphs the registering instruments will beenabled to record as much as a given wire can transmit; and it isexceedingly probable that by the use of my key in connection with theduplex system it will be found that the electro-magnets of the registerswill be enabled to record just as much as the line-wire will transmit,owing to the effect of retardation diminishing the capacity fortransmission of all line-wiresin other words, that my key, in connectionwith the duplex, will accomplish far more and with far greatersimplicity the transmission ofa given amount of message-matter over agiven Wire than the quadruplex can ever hope to attain.

Having thus described the construction, operation, and application of myimproved telegraph-key, what I claim is- 1. The finger-springs ed, incombination with the finger-keys K and K and insulated cores tosubstantially as and for the purpose described.

2. The finger-keys K and K, having springs g applied thereto, as shown,in combination with the metallic letters V substantially as and for thepurpose described.

3. The bar Q, with its supports T and T and adjusting-screws w, incombination with the metallic letters V substantially as and for thepurpose described.

HENRY MIDDLETON.

Witnesses:

W. ALs'r0N PRINGLE, WM. P. DE SAUSSURE.

